The server communicates with Oracle anytime someone runs an Oracle query from a IIS page. I was continually getting ORA-12541: TNS: no listener when trying to access a remote Oracle data source from IIS on Server 2008 using the Oracle ODBC driver. I was finally able to get it to work by placing the tnsnames.ora file into the C:\Windows\SysWOW64\inetsrv directory which is the default directory for the IIS worker process, w3wp.exe. Since that is quite a hack, I am going to see if there is a way to get the Oracle driver to check the normal places while running under in w3wp.exe.

The server communicates with Oracle anytime someone runs an Oracle query from a IIS page. I was continually getting ORA-12541: TNS: no listener when trying to access a remote Oracle data source from IIS on Server 2008 using the Oracle ODBC driver. I was finally able to get it to work by placing the tnsnames.ora file into the C:\Windows\SysWOW64\inetsrv directory which is the default directory for the IIS worker process, w3wp.exe. Since that is quite a hack, I am going to see if there is a way to get the Oracle driver to check the normal places while running under in w3wp.exe.

You appear to be hijacking someone else's old thread. Nevetheless ..

tnsnames is not used by IIS. It is only used by Oracle components, which in your case starts with the ODBC driver, which makes a call to the standard Oracle client libraries. Which means you have the Oracle client installed. Which means you have an ORACLE_HOME directory. tnsnames.ora is properly (and by default) located in ORACLE_HOME/network/admin.